Embodiments of the present invention relate generally to the field of warehouse management systems and more particularly to using access point triangulation in assignment of tasks to warehouse employees.
Large warehouses storing a wide variety of items are typically managed by warehouse management systems (“WMS”) that are used to track inventories of items within the warehouse, receive and handle orders for those items, and assign warehouse employees to fill those orders. A WMS is often a complex software package that run on top of a relational database management system (“RDBMS”), such as the Oracle 10 g RDBMS. Oracle Warehouse Management is one example of such a package.
Generally speaking, when an order for an item stored in a warehouse is received, the WMS will assign a task, known as a pick task, to one or more warehouse employees to retrieve the item or items requested by the order from the warehouse to fill the order. One goal of the WMS application is to efficiently allocate tasks to the warehouse employees. Previously, such assignments were made largely at random. More recently, attempts have been made to improve the efficiency of job assignments. This is accomplished by dividing the warehouse into regions or zones with one or more employees assigned to a particular zone. The WMS then determines the zone in which a requested items is located and assigns a pick task for that item to the employee(s) assigned to that zone. That is, the task assignments are made on a per-zone basis.
However, this approach is somewhat inefficient. More specifically, depending upon the items requested, some zones and the employees therein may be idle while other zones are over worked. For example, one item or type of item, such as holiday decorations or a particular toy, may be seasonally very popular. The employee or employees working in a warehouse zone in which such items are stored may be extremely busy filling orders for those items while employees in another zone may be idle.
Furthermore, such a system that assigns tasks on a per-zone basis does not take into consideration an employee's movements throughout the zone or the warehouse while performing various tasks. For example, an employee may move into and out of an assigned zone while performing a pick task or the zone may be vary large causing the employee to move a considerable distance to complete a task. Assigning the tasks based on the zone without consideration of an employees movements leads to inefficiencies since another employee may be closer to a requested item and can more easily fill a request for that item.
Some WMSs try to account for movement of the warehouse employees by allowing or requiring an employee to check into or out of a zone as the employee moves about. That is, the employees can check into a zone when they enter that area, thereby making themselves available for pick tasks within that zone. However, such a check-in and check-out system can actually compound inefficiencies. If an employee fails to check into a zone or check out of his previous zone, assignment of tasks becomes inaccurate and inefficient.
Another approach has been to allow or require the employees to accept or requests new tasks. That is, the employees could request a task and the WMS would find one, either at random or based on the employee's zone, and assign the task to that employee. However, this can also be ineffective and/or inefficient since it can be heavily affected by employee morale and performance and does not address the other shortcomings of a zone-based system.
Hence, there is a need in the art for more efficient methods and systems for assigning tasks to warehouse employees.